There are a great many nutrition-related digestive problems, including inflammatory bowel disease, celiac disease, non-celiac gluten sensitivity, small intestinal bacterial overgrowth, and gastroesophageal reflux disease. Will a low-FODMAP diet help any of them? Your own doctor and dietitian can help you decide if the FODMAP approach is right for you. If you have any of these conditions, your FODMAP-elimination and challenge process will probably need to be customized for you by a qualified dietitian.

Inflammatory bowel disease (IBD): It appears unlikely that a low-FODMAP diet is capable of inducing or maintaining remission in patients with Crohn's disease or ulcerative colitis. Still, a low-FODMAP diet might still be able to help manage symptoms and improve quality of life. People with IBD can also have IBS. When patients with Crohn's or ulcerative colitis in remission are still symptomatic, IBS and FODMAPs could be to blame. During an flare-up of IBD, it stands to reason that one should limit foods that might cause osmotic diarrhea on top of the IBD symptoms. For example, it doesn't make sense to replace fluids during bouts of diarrhea with high FODMAP beverages, such as fruit juice or regular milk. Patients with IBD will want to approach reintroduction of FODMAPs with more caution than other people.

Celiac disease (CD): People with celiac disease are far more likely to have IBS than other people. If you have celiac disease, eat a gluten-free diet, and still experience excess gas, abdominal pain, bloating, diarrhea or constipation, FODMAPs could be to blame. First, though, talk with your doctor to make sure your gluten antibody levels reflect a 100% gluten-free diet and ask an expert in gluten-free eating to review your diet for hidden sources of gluten. Then consider a trial FODMAP-elimination diet to see if your symptoms improve. Be especially watchful of FODMAP ingredients added to boost the fiber content of gluten-free breads and baked goods.

Non-celiac gluten sensitivity (NCGS): A person with NCGS has observed that he or she has a bad reaction to gluten, even though celiac disease has been ruled out. There is no biomarker (specific test) for NCGS. This condition reportedly accounts for over half of the patients seen in celiac specialty clinics. There is some debate about whether the NCGS gastrointestinal symptoms attributed to gluten might really be due to the FODMAPs present in gluten grains.

Small intestinal bacterial overgrowth (SIBO): Healthy people have very few bacteria living in their small intestines. If an overgrowth of bacteria in the small intestine develops, which can happen for a variety of reasons, IBS-like symptoms can occur. Research is ongoing to determine the best ways to diagnose and treat SIBO, and to find out how many people previously diagnosed with IBS actually have SIBO. Firm practice guidelines don't exist yet, but antibiotic treatment shows the most promise. It seems likely that a diet low in rapidly fermentable carbohydrates, such as a low-FODMAP diet, would discourage relapse of SIBO after antibiotic treatment. However, there have been no scientific experiments yet to prove whether this or any other diet is best for people with SIBO.

Gastroesophageal reflux disease (GERD): GERD is a very common condition; a great many people with IBS also have GERD. FODMAPs exert their direct effect in the lower part of the gastrointestinal tract, and FODMAP studies have not looked at GERD symptoms, such as heartburn, directly. Still, many people do report fewer GERD symptoms on the FODMAP-elimination diet. With less excess gas and fluid distending the intestines, perhaps there is less upward pressure on the stomach to encourage reflux. Or perhaps the extra attention to healthy food choices and smaller portions during the low-FODMAP diet reduces reflux.

“IBS: Free at Last” is not aimed at those with severe bowel disease, but I can tell you it is well worth reading this book and trying the FODMAP diet anyway. For years my husband has suffered the ghastly symptoms of severe ulcerative colitis, unable to work out why some foods this week set it off when they were fine last week. In desperation, we tried the FODMAP diet as set out in this book and the results have been amazing. My husband’s horrid symptoms disappeared within 4 days of starting the elimination diet. He has been continually free of the horrid symptoms for two months now and feels terrific - like a man 20 years younger, he says. I have noticed a huge change in his outlook on life - he is much more confident and cheerful. A recent colonoscopy confirmed that he still has severe Ulcerative Colitis, and we knew the FODMAP diet would not cure him of that. But the FODMAP diet has given us a good solid basis from which to control the symptoms. Patsy, I can’t thank you enough. This diet has changed our lives.